58o RESEARCHES ON FUNGI 



basidiospores but, in their gills, they develop large numbers of sniooth 

 chlamydospores which doubtless serve to propagate the species. J^rom 

 the point of view of sex, the life-history of N. farasihca appears to 

 resemble that of N. asterophora. . , , 



Stropharia epimyces completely masters its host, causmg deformation 

 and sterility of the fruit-bodies of Coprinus comatus and C. atmmentanus 



which are attacked. 



The supposed fungus Tremella mycetophila is not a tremeJlaceous 

 parasite on Collyhia dryophila but merely an abnormal excrescence of 

 C dryophila itself, resembhng a Tremella in general form. 



Collyhia velutipes, like C. dryophila. sometimes develops abnormal 

 fruit-bodies. Some of these are morchelloid m appearance. 



Chapter XIV —The author, with the aid of a beam of light emitted 

 from an electric hand-lamp, has studied the nocturnal discharge of spores 

 of fruit-bodies of Pleurotus ostreatus and Collyhia velutipes growing 



in the open. . • . i 



Some fruit-bodies of Pleurotus ostreatus growing m the open near 

 Birmingham, England, liberated spores continuously throughout the 

 month of December. The spores were emitted much more freely at 

 high temperatures than at low. At 48° F. the fruit-bodies gave off . 

 spores so rapidly that the spore-clouds could be seen coming away from 

 the gills during the day. Night observations with the hand-lamp showed 

 that very faint spore-clouds were being emitted even when hoar-frost 

 was forming on a near-by la^v^l and the temperature of the air surround- 

 ing the fruit-bodies had become reduced to 34° F. 



Collyhia velutipes, the Velvet-stemmed Collyhia or Winter Mush- 

 room is very resistant to frost and is commonly found in Eng and and 

 the United States in the late autumn and winter months. At night, 

 with the help of the hand-lamp, some fruit-bodies were observed to be 

 shedding spores from December 23 to December 30. The discharge of 

 spores was more active on warm nights than on cold. 



PART II 



Chanter I —In the Uredineae and the Hymenomycetes the basidio- 

 spores are arranged on their sterigmata and are discharged in identically 



the same manner. ■ ^ £ ■ , ^t 



In the Uredineae and the Hymenomycetes, from the point of view ot 

 structure • (1) at the beginning of its development a basidiospore always 

 forms a small projection-the spore-hilum-^t the point where it joins 

 the sterigma and on one side of it, and (2) the axis of a spore taken 

 through its point of attachment is always inchned to the axis of the 

 sterigma. 



